Slotted alternator brackets have been in common use for over the last thirty years for receiving an alternator carried fastener that permits the alternator when the fastener is loosened to pivot as the fastener slides in the slot to tension the alternator belt. When the proper tension is achieved the fastener is retightened locking the alternator in the adjusted position with the proper belt tension.
This procedure usually includes the use of either a large screwdriver, wrench or bar to assist the mechanic in providing pressure to the housing of the alternator to achieve sufficient leverage in pivoting the alternator to properly tension the belt.
While various leverage achieving mechanisms including gearing have been suggested in the past for adjusting alternator belt tension, as well as belt tensioning applications in general, these have not achieved any considerable degree of commercial success in the automotive alternator environment for two reasons. One is the mechanisms have been difficult to use and since the prior method of utilizing a tool to leverage the alternator is not overly complex, the mechanic certainly would not substitute a more complicated procedure for one that is simpler.
The second reason these prior belt tensioning devices have not achieved any material success in the automotive alternator application is because of their extreme complexity, they add a sufficient cost increment to the tensioning device that makes them unattractive for the high volume OEM automobile market.
One such alternator belt tensioning mechanism is shown in the Hurst et al. U.S. Pat. No. 3,430,507 which illustrates a pivotally mounted generator that has a bolt fixed to one side of its housing extending through a slot in an adjustable bracket having a rack on its outer periphery. A pinion mounted separately from the bracket or strap and also separately from the alternator engages the rack to provide adjustability while the fastener holds the bracket tightly to the alternator. Because the pinion is mounted separately from the bracket and the alternator the assembly is very complex, expensive to manufacture and also increases the envelope required in the engine compartment.
There are also a plurality of treaded fastener tension adjusting mechanisms adjacent alternator bracket slots wherein the threaded fasteners are carried by a bracket fixed to the alternator adjacent the bracket slot. Such mechanisms are illustrated in the Shiki, et al. U.S. Pat. Nos. 3,922,927, the Brenneman 4,512,752, and the Isobe, et al. 4,571,221.
There are also a plurality of general purpose rack and pinion or chain belt tightening mechanism but none are adapted to be compatible with conventional alternator brackets. These include the ones shown in the Johnston U.S. Pat. Nos. 630,833, the Moran 687,252, the Swift 2,074,078, the Hupp 2,709,493 and the Gerrans 3,004,443. Other general purpose belt tighteners are shown in the Aikman U.S. Pat. Nos. 2,184,541, the Sauer 2,205,176 and the Estes 2,970,587.
It is the primary object of the present invention to ameliorate the problems noted above in vehicular alternator belt tensioning devices.